ASA 125th Meeting Ottawa 1993 May

4aUW8. Target tracking using matched-field processing.

Michael J. Wilmut

Royal Roads Military College, FMO Victoria, BC V0S 1B0, Canada

John M. Ozard

Bryan Woods

Defence Res. Establishment Pacific, FMO, Victoria, BC V0S 1B0, Canada

The objective of this paper is to illustrate the use of matched-field
processing (MFP) for tracking low signal-to-noise ratio targets moving linearly
and at constant speed. The input to the tracker consists of the positions and
power of the largest peaks on the MFP ambiguity surface. These largest peaks
usually include the match at or near the source position even at low
signal-to-noise ratio. An exhaustive search for the best matching track over
all possible target tracks (that is allowing varying speed and heading) is
beyond the scope of today's computers for any realistic search region. In this
paper, an efficient algorithm is described based on examining the average
Bartlett statistic along a set of linear tracks that connect only the largest
peaks. This set was restricted to the physically possible tracks to further
reduce the number to be examined. Examples of the ambiguity surfaces and the
probability of examining the true track are given. The algorithm performance is
a function of the scenario, signal-to-noise ratio, number of ambiguity
surfaces, and number of peaks examined on each surface. It is shown that if the
true target track is one of those examined its Bartlett statistic is almost
certainly maximum. This efficient tracking requires only modest computing
beyond that required to generate the ambiguity surfaces.